RE: Core One MMU3 Prototypes
I don't think so; I just published the file "PrusaCoreOne_TopCover_Cutted.step" that might meet this need : https://www.printables.com/model/1283543-prusa-core-one-mmu3-install-and-mmu3-setup
Perfect - thank you! I'm sure I can export that in a format suitable for the local plastics guy. I think he uses some program from Corel, but I know he can work with my PDFs.
I got a new pre-cut top from the local plastics guy. I used Prusaslicer to convert your STEP file to an STL, then used OpenSCAD to convert it to 2D and export a half-sized PDF and a DXF. AutoCAD didn't like OpenSCAD's DXF, but I was able to import the PDF, scale it back up and then copy the vent hole pattern to make the sliding vent piece as well. I then saved it as a DXF and also exported a full-sized PDF. The PDF is what my local plastics guy used.
He didn't have any smoked acrylic to match the original, se we settled on 2mm clear cast acrylic. It fits perfectly. Now to print the other bits of dancan13f's model.
RE: Core One MMU3 Prototypes
I don't think so; I just published the file "PrusaCoreOne_TopCover_Cutted.step" that might meet this need : https://www.printables.com/model/1283543-prusa-core-one-mmu3-install-and-mmu3-setup
Perfect - thank you! I'm sure I can export that in a format suitable for the local plastics guy. I think he uses some program from Corel, but I know he can work with my PDFs.
I got a new pre-cut top from the local plastics guy. I used Prusaslicer to convert your STEP file to an STL, then used OpenSCAD to convert it to 2D and export a half-sized PDF and a DXF. AutoCAD didn't like OpenSCAD's DXF, but I was able to import the PDF, scale it back up and then copy the vent hole pattern to make the sliding vent piece as well. I then saved it as a DXF and also exported a full-sized PDF. The PDF is what my local plastics guy used.
He didn't have any smoked acrylic to match the original, se we settled on 2mm clear cast acrylic. It fits perfectly. Now to print the other bits of dancan13f's model.
Would you be willing to share the PDF?
RE:
Would you be willing to share the PDF?
Of course - here you go. The zip contains the DXF as well as the PDF.
RE: Core One MMU3 Prototypes
Congratulations; great work.
Do you allow me to publish your files (DXF and PDF) on my model ( https://www.printables.com/model/1283543-prusa-core-one-mmu3-install-and-mmu3-setup) ?
RE: Core One MMU3 Prototypes
Congratulations; great work.
Do you allow me to publish your files (DXF and PDF) on my model ( https://www.printables.com/model/1283543-prusa-core-one-mmu3-install-and-mmu3-setup) ?
Yes - please do.
RE: Core One MMU3 Prototypes
It's done ; thank's 😉
RE:
I printed the PTFE guide pieces in Prusament ASA and they fit into the corner nicely. I had not appreciated that they are fixed to the frame and that the acrylic lid just slots in around the PTFE guide and remains easily removable - that's quite neat. I long ago removed the rivets and made some magnetic pucks for the corners of the lid.
Next step is to move the MMU rail onto the back, where dancan13f intended - the right side mounting isn't going to work until I can find a longer (~1m) MMU cable than either of the sources I'm aware of (Prusa @80cm and Blurolls @70cm). Then I'll need to consider whether to go with a bigger buffer (such as dancan13f's) or experiment with rewinders. And I'll need to find some desk space for the spools! In my MK4+MMU3 setup I have 5 spoolholders inside the enclosure.
RE: Core One MMU3 Prototypes
Nice work. Here is my take on it. I used the Prusa designed MMU3 brackets and jade a couple extra cuts to clear them. 
RE: Core One MMU3 Prototypes
The Blurolls store on AliExpress has kindly just offered to make me a bespoke length of MMU cable, so I'm going to check my measurements and then order one - it'll be around 100 to 110cm I think. It's a bit more expensive, and the lead time is longer, but nevertheless it's good of them to accommodate my request. This will allow me to mount the MMU on the right side of the CORE One, which will be much more convenient for me in my setup. It'll give me options for the filament routing I think - possibly through dancan13f's adapter in the top plate, possibly through the original feed point on the right hand panel.
I'm not discounting the possibility that the extra cable length may cause problems with the MMU - I haven't looked into what the wires carry, but I have a vague understanding that if it's carrying time-sensitive data, or uses high speed differential signalling then there could be issues. Only one way to find out though....
RE: Core One MMU3 Prototypes
Any chance of others getting in on this?
The Blurolls store on AliExpress has kindly just offered to make me a bespoke length of MMU cable, so I'm going to check my measurements and then order one - it'll be around 100 to 110cm I think. It's a bit more expensive, and the lead time is longer, but nevertheless it's good of them to accommodate my request. This will allow me to mount the MMU on the right side of the CORE One, which will be much more convenient for me in my setup. It'll give me options for the filament routing I think - possibly through dancan13f's adapter in the top plate, possibly through the original feed point on the right hand panel.
I'm not discounting the possibility that the extra cable length may cause problems with the MMU - I haven't looked into what the wires carry, but I have a vague understanding that if it's carrying time-sensitive data, or uses high speed differential signalling then there could be issues. Only one way to find out though....
RE: Core One MMU3 Prototypes
Any chance of others getting in on this?
I don't really know how Blurolls operate in this respect. I'm not going to order more than the one I need, but if I mention to them that there may be interest from other buyers maybe they'd consider making a small batch. I'll ask when I place my order.
RE: Core One MMU3 Prototypes
I just rechecked the measurement - with dancan13f's mounting rail fixed to the top-right frame rail, and the MMU pulled all the way to the front of that rail, the cable needs to be 36/37cm longer. This would be with the cable trailing round the back of the printer until it reaches the cable cutout in the back cover. I did not remove the existing MMU cable to measure it, but using a bit of string it seems to be about 58/59cm long. So I'm going to order a nice round 1m, to leave a little bit of slack.
RE: Core One MMU3 Prototypes
Any chance of others getting in on this?
I don't really know how Blurolls operate in this respect. I'm not going to order more than the one I need, but if I mention to them that there may be interest from other buyers maybe they'd consider making a small batch. I'll ask when I place my order.
What parts does the cable comprises of? Is it simply molex plugs with a simple pin out? If I have the correct crimp tool and pi otu for the connectors, I may be able to make these up.
Scott
RE: Core One MMU3 Prototypes
What parts does the cable comprises of? Is it simply molex plugs with a simple pin out? If I have the correct crimp tool and pi otu for the connectors, I may be able to make these up.
Scott
I don't know what range the plugs are from, but the pinouts can be easily copied. I was thinking along the same lines, and that was my fall-back option. But for circa $20 I figured I'd struggle to beat that. I'd have to identify the connectors and then probably have to buy 10 of each, then a packet of 50 or 100 crimp terminals, and various different wire thicknesses/colours, and some cable wrap. In the end it just seemed easier to give the job to someone who's worked through all this already, and has the parts to hand 🙂
RE: Core One MMU3 Prototypes
Hi Chris, thanks for your effort.
I'd also be very interested in a slightly longer MMU cable. My idea is to place the MMU in the right-hand recess to access the original filament path. If you already have the CoreOne, could you please measure how long the cable would need to be from the opening on the Buddy Box to the lower front corner of the right recess?
By the way, I don't think the cable length is critical for data transfer. High-speed is certainly not necessary for the few control commands. And the MMU-protocol already dates back to the i2/i3 series. Back then, things were a bit more relaxed. 🙂
RE:
Hi Chris, thanks for your effort.
I'd also be very interested in a slightly longer MMU cable. My idea is to place the MMU in the right-hand recess to access the original filament path. If you already have the CoreOne, could you please measure how long the cable would need to be from the opening on the Buddy Box to the lower front corner of the right recess?
By the way, I don't think the cable length is critical for data transfer. High-speed is certainly not necessary for the few control commands. And the MMU-protocol already dates back to the i2/i3 series. Back then, things were a bit more relaxed. 🙂
In that location I think the path length would be very similar to when the MMU is on the front of the top rail. My MMU is back on my MK4S now, so I've done my best to estimate with a bit of string, and the path length may be a few cm shorter than in my case, but I think I'd go for a 1m total length to be on the safe side.
EDIT: Actually, if you take out all the slack, there's a chance that Prusa's 80cm cable might work - I'll need to lift the CORE One down again to check properly.
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If you take out all the slack, 80cm gets you to about here if you go via the cable cutout in the back cover.
And for the sake of completeness, 80cm might just be enough for the top rail, although maybe not the front of the top rail, and with the cable pulled tight. I'm going to stick with my 100cm order.
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The MMU is controlled via the RS-485 interface.
Regarding data rate vs. cable length, Wikipedia says:
"RS-485 supports inexpensive local networks and multidrop communications links, using the same differential signaling over twisted pair as RS-422. It is generally accepted that RS-485 can be used with data rates up to 10 Mbit/s[a] or, at lower speeds, distances up to 1,200 m (4,000 ft).[2] As a rule of thumb, the speed in bit/s multiplied by the length in meters should not exceed 10e8. Thus, a 50-meter cable should not signal faster than 2 Mbit/s.[3]"
From this, I conclude that extending the cable by a few centimeters does not affect data transmission from /to MMU.
RE: Core One MMU3 Prototypes
To be on the safe side, I prefer a length of 1.20 m. Can you tell me the source at Blurolls/Ali where I can order this?
RE: Core One MMU3 Prototypes
From this, I conclude that extending the cable by a few centimeters does not affect data transmission from /to MMU.
Good work 👍
To be on the safe side, I prefer a length of 1.20 m. Can you tell me the source at Blurolls/Ali where I can order this?
I simply messaged the seller of this item.